1. Field of the Invention
The present invention relates to a system and method of controlling a photovoltaic device.
2. Description of the Related Art
A photovoltaic (PV) device may be in the form of a cell, module or array. In order to extract maximum power from such a PV device, the device may be operated at the maximum power point (MPP) on the current vs. voltage (I-V) curve for that device, as shown in FIG. 1. Because this maximum power point varies with irradiance, temperature, aging, and other conditions, PV systems employ a function known as Maximum Power Point Tracking (MPPT) in order to keep the PV devices operating at or close to the MPP. The MPPT function is typically performed using circuitry and algorithms within the Direct Current (DC) to Alternating Current (AC) PV inverter (referred to herein as the “inverter”) connected between the PV devices and utility grid or AC electrical loads. Alternately, the MPPT function may also be implemented as circuitry and algorithms within a DC optimizer (or DC/DC converter) connected directly to the PV devices, as shown in system 20 of FIG. 2.